First Human Case of Avian Flu in the U.S. Confirmed in Colorado

The Centers for Disease Control and Prevention (CDC) announced on Thursday that a person in Colorado has tested positive for avian influenza.

The Colorado Department of Public Health and Environment (CDPHE) said the man is mostly asymptomatic, reporting only fatigue. He is now isolating and taking the antiviral drug oseltamivir (Tamiflu) per CDC direction.

“This case occurred in a person who had direct exposure to poultry and was involved in the culling (depopulating) of poultry with presumptive H5N1 bird flu,” the CDC reported in a press release. 

This is the first human case in the U.S. associated with this specific group of H5 viruses that are currently predominant. 

The last major outbreak of H5N1 in 2015 the was the worst animal disease outbreak recorded in U.S. history, according to the USDA. Officials are concerned 2022 outbreaks could surpass that year.

Risk Of Infection Is Low

The CDC said it is possible the detection of H5 bird flu in this “specimen is a result of surface contamination of the nasal membrane, that can’t be determined at this point and the positive test result meets the criteria for an H5 case. The appropriate public health response at this time is to assume this is an infection and take actions to contain and treat.”

This case does not change the human risk assessment for the general public, which CDC considers to be low. However, people who have job-related or recreational exposures to infected birds are at higher risk of infection should take appropriate precautions outlined in CDC guidance.

Monitoring Is Ongoing

CDC has been monitoring for illness among people exposed to H5N1 virus-infected birds since these outbreaks were detected in U.S. wild birds and poultry in late 2021 and into 2022.

To date, H5N1 viruses have been found in U.S. commercial and backyard birds in 29 states and in wild birds in 34 states. CDC has tracked the health of more than 2,500 people with exposures to H5N1 virus-infected birds and this is the only case that has been found to date. Other people involved in the culling operation in Colorado have tested negative for H5 virus infection, but they are being retested, CDC said.

More information is available at www.cdc.gov/media/releases/2022/s0428-avian-flu.html